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	Soil shrinkage and hydrostructural characteristics of three swelling soils in Shaanxi, China
	Huang C. Q. ; Shao M. A. ; Tan W. F.
	2011
关键词	Anisotropy Geometry factor Pedohydral parameter Shrinkage modeling Soil shrinkage clay soil hydraulic-properties texas vertisols volume change curve cores geometry
英文摘要	Knowledge of soil shrinkage is important for a better understanding of water and solute transport in swelling soils. The objective of this study was to investigate the shrinkage processes and characteristics of three typical swelling soils in Shaanxi, China, with different height treatment using a modified core method and to analyze their agronomic properties. Three swelling soils, Calcarit Regosol, Eutric Cambisol, and Cumulic Anthrosol, collected in Ansai, Ankang, and Yangling, respectively, were investigated. The experimental procedure consisted of the simultaneous measurements of the height (H), diameter (D), and mass (m) of initially saturated soil core samples during dehydration by evaporation. The results showed that soil texture (clay content) and structure [bulk density (rho (b) )] affected the shape of soil shrinkage characteristic curve (SSCC), but the sigmoid shape of the shrinkage curve could be regarded as a general characteristic for well-structured soils. The influence of core sample height on the shrinkage characteristics was due to the pressure increase resulting from the overlaying soil mass. The computer code (CARHYS) proposed for soil hydrostructural characterization was applied to analyze the discontinuous SSCC data. The computer calculations revealed that it could fit the data very well with a correlation coefficient > 0.9755 for the three soils and determine characteristic transition points of all of the different phases of SSCC accurately. Analysis of the geometry factor exhibited that soil shrinkage was anisotropic and only subsidence of soil surface happened at the beginning of shrinkage. According to the relation between the transition points in the SSCC and the particular soil moisture states available water (AW), readily available water (RAW), air capacity (AC), and swell-shrink potential (coefficient of linear extensibility (COLE)) were calculated from the parameters obtained by CARHYS. AC of the soils was consistent with rho (b) . AW and RAW were affected by both clay content and rho (b) . The investigated soils were all ranked in the low-swelling class according to the classification of the US Department of Agriculture. Next to clay content, rho (b) should be considered as an important physical factor affecting the agronomic properties and the swell-shrink behavior of the soils. Application of the computer code (CARHYS) to analyze the discontinuous shrinkage characteristics curves and to determine the water-holding characteristics (AW, RAW) and other structural properties (AC, COLE) is feasible. The analysis provided a good insight in the swelling-shrinkage properties and the hydrostructural characteristics of the investigated soils.
出处	Journal of Soils and Sediments
卷	11
期	3
页	474-481
收录类别	SCI
语种	英语
ISSN号	1439-0108
内容类型	SCI/SSCI论文
源URL	[http://ir.igsnrr.ac.cn/handle/311030/23836]
专题	地理科学与资源研究所_历年回溯文献
推荐引用方式 GB/T 7714	Huang C. Q.,Shao M. A.,Tan W. F.. Soil shrinkage and hydrostructural characteristics of three swelling soils in Shaanxi, China. 2011.

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